Both 命 (めい) and 題 (だい) are read with their On'yomi. This is a standard pattern for many two-kanji nouns, especially in academic contexts. めいじ or めいし are misreadings of 題. It refers to a statement or assertion that is either true or false, often used in logic and mathematics.

命（めい）と題（だい）は共に音読みです。めいじやめいしは題の誤読です。真偽を判定できる文や主張を指す、論理学や数学で用いられる用語です。